<!DOCTYPE html>
<title>Flex painting order with z-index</title>
<link rel="author" title="Martin Robinson" href="mailto:mrobinson@igalia.com">
<link rel="help" href="https://drafts.csswg.org/css-flexbox/#painting">
<meta name="assert"
  content="z-index works on flex items even though they do not have `position: relative`" />
<link rel="match" href="../reference/ref-filled-green-100px-square.xht">

<style>
    #flex {
        display: flex;
        width: 100px;
        height: 100px;
    }

    #flex > div {
        width: 0px;
        height: 0px;
    }
    #flex > div > div {
        width: 100px;
        height: 100px;
    }
</style>

<p>Test passes if there is a filled green square and <strong>no red</strong>.
</p>

<div id="flex">
    <div><div style="background: green"></div></div>
    <div style="z-index: -10"><div style="background: red;"></div></div>
</div>
